Checkerbrick



C. H. HUGHES CHECKERBRICK Filed April 11, 1931 Sept. 26, 1933.

- 2 Sheets-Sheet 2 INVENTOR C/mr/es 1V. fluyfies BY 4 6 ATTORNEY zww Patented Sept. 26, 1933 UNITED STATES CHECKERBRICK I Charles H. Hughes, Glen Ridge, N. J., assignor Semet-Solvay Engineering Corporation,

New York, N. Y. a corporation of New York Application April 11, 1931. Serial No. 529,333 v 3 Claims. (01. 2 3-51) This invention relates to improvements in refractory material, and more particularly to the construction and arrangement of the checkerbrick in the carburetor and superheater units 5 utilized in the manufacture of carburetted water gas, oil gas, low gravity gas, and. the like. It is an object of this invention to provide in carburetting apparatus, oil cracking chambers and the like, a checkerbrick of novel design by the use of which the heating and exposed surface of such brick is increased per cubic foot of the ckerwork. 1

It is a further object of the present invention to provide a checkerwork composed of intact of adjacent checkerbrick affords a single wall thickness, thereby avoiding double wall thicknesses at the joints which tend to reduce the uniformity of the rate of heat transfer between the checkerbrick and the gas passing thereover.

Another object of this invention is to provide checkerbrick which combines a thin heating wall with strong structural characteristics particularly designed for use in the carburetors and superheaters of a water gas plant in which the alternating blast and gas making cycles are of short duration, from two to three minutes. In the construction of carburetting apparatus and oil cracking apparatus of water gas sets, it is the usual practice to build up the interior of, the carburetting and superheating chambers of checkerbrick, i. e. of irregular ceramic particles which function as heat transfer bodies and also as igniters, as hereinafter more fully explained. During .the initial blasting cycle, air or other oxygen containing gas, is passed through the fuel bed of the generator, thus forming producer or blast gases which, at a temperature of approximately 780 C., are passed through the carburetting and superheating chambers over the checkerbrick therein. To utilize both the sensible and latent heat of the blast gases, secondary air is admitted to the carburetor. and superheater. The checkerbrick, heated by the hot gases passing thereover, ignite the mixture of-blast gases and air. Thus, both the sensible and latent heat of the blast gases are utilized in bringing the temperature of the checkers to the desired point for the subsequent gas making cycles.

This blasting cycle is continued for approximately three minutes and thereafter introduction of air into the fuel bed and the passage of the resultant blast gases through the carburetor dividual brick units wherein the point of con-I and superheater are discontinued. Steam is then introduced into the generator and passed through.

the fuel bed therein, the resultant water gas being passed through the carburetor. Y .Oilis in-- troduced into the carburetor and cracked by contact with the checkerbrichthe resultant water gas and oil gas being passed through the car-' bure'tor and superheater over the hot checkerbrick and fixed'in their passage through these chambers. To efficiently fixthe'carburetted water gas, it is'essential that the heat stored in' the checkerbrick be utilized for this purpose. This run, called the uprun, usually lasts approximately two minutes.

Following the uprun', in accordance with preferred practice, steam is introduced into the superheater, passed therethrough intoand through the carburetor, into the generator, down through the fuel bed therein, the resultant water gas being withdrawn from the base of the generator. The steam in itspassage through the superheater and carburetor is superheated. Obviously, increasing the effective surface of the checkers over which the steam passes and improving the rate of heat transfer between the'checkers and the steam would result in greater amounts of heat being imparted to the steam. This cycle, commonly called the backrun cycle, alsolasts about two minutes. Thereafter, the fuel bed is again blasted and the uprun and backrun gas making cycles repeated in'the sequence noted or in teverse sequence as may be desired.

Heretofore, the carburetor and superheater of water gas sets have been filled with a refractory clay checkerbrick, approximately 9 inches long, 4 inches high, and having a wall thickness of 2% inches, which checkers are commonly employed in regenerative furnaces which operate upon a 20-minute reversal cycle, i. e., for 20 minutes hot products of combustion, at a temperature of approximately 1250 C. pass over the checkers, heating the same and for the next 20 minutes, the gas to be heated is passed over the hot checkers, absorbing the heat thereof. Operating upon a 20-minute reversal cycle and at the temperatures prevailing in regenerative operations, it has been found that the heat penetrates throughout the thickness of such clay checkers. In water gas operation, as above pointed out, the blow period lasts approximately three minutes. I have found that the checkerbricks of the type previously used are heated to a depth of not over to inchand that with checkers of 2 inch thickness it is only the to inch thickness thereof adjacent. to the surface that isactive, the

brick to form fiues. brick defines one flue and the projecting por-' remaining interior portion of the brick being inactive with respect to the transfer of heat to gas passing therethrough. The inactive portion of the brick occupies space in the carburetor and superheating chambers which is not beneficially utilized in the gas making process.

In accordance with my invention, a checkerbrick comprising a hollow parallelepiped, each of the walls which is provided with projecting portions extending beyond the corner edges of the parallelepiped a distance equal to one-half the length of the wall, is laid with other like checker- The hollow portion of each tions at a corner of each brick cooperate with projecting portions at the corners of contiguous bricks to define a like flue. brick transverse to the fiues has'projections thereon which are arranged to space superimposed bricks apart so as to provide a passage between adjoining fiues. By interconnecting adjoining fiues, a tortuous passage through the fiues is provided, thereby increasing the length of the path of flow of gas therethrough and consequently increasing the time of contact of the gas with theheated checkers. Preferably, but not necessarily, the brick is made of a thickness of substantially less than two and one-half inches, say from one to one and one-half inches, so that when the checkers are employed in the carburetors or superheaters of water gas sets, the entire thickness of the checkers functions to store heat during the blasting cycle and transfer this heat in fixing the water and oil gas and superheating the steam as-the case may be during the alternate gas-making cycles.

Other novel features of construction and arrangement of parts will appear from the following description.

In the accompanying drawings which are, however, merely intended to illustrate the preferred embodiment of my invention, without limiting the scope of the latter to the construction shown:

Fig. 1 is a side elevation, partly in section, of a water gas set, the carburetor and superheater of which are filled with checkerbrick of my invention;

Fig. 2 is a plan view of one course of checkerbrick laid in accordance with the preferred embodiment of my invention;

Fig. 3 is a plan view of two courses of checkerbrick wherein the individual checkers of adjacent courses are laid in staggered relation with respect to one another;

' Fig. 4 is a perspective view of the preferred form of checkerbrick of my invention;

Fig. 5 is a perspective view of a fragment of two staggered courses of checkerbricks shown in Fig. 3;

Fig. 6 is a perspective view of a modified form of the checkerbrick shown in Fig. 4;

Fig. '7 is a perspective view of a further modifled form of the checkerbrick shown in Fig. 4;

Fig. 8 is a plan view of two courses of checkerbrick laid with the form of checkerbrick shown in Fig. 7; and

Fig. 9 is a side elevation of the two courses of checkerbrick shown in Fig. 8 taken on the line 9-9 of Fig. 8.

In the drawings, with particular reference to Fig. 4 which illustrates a preferred embodiment of the invention, the checkerbrick comprisesa hollow parallelepiped section 2 defined by the sides 3 which preferably are of equal length. On each corner of section 2, there are two pm- One face of each jections 4 of the same height as the sides 3, but of a length equal to approximately one-half of the length of the sides 3. It will be noted that the projections 4 are in reality continuations of the sides 3 of the hollow square 2 and accordingly are positioned at right angles to one another. The dimensions of sides 3 and of the projections 4 may be varied as desired. I have found that a checkerbrick, the walls of which are 1%" thick, the length of sides 3, 2%", 3" or 4", the length of projections 4, 1 /4", 1 /2" or 2" depending upon whether 2 3", or 4" fiues respectively are desired, and of a height of 4 /2" is admirably suited for carburetor and superheater construction. Preferably the wall thickness of the brick is from linch to 1 inches.

In the preferred embodiment of my invention, the bricks are laid in adjacent and superimposed relation, as shown in Fig. 2, to form a series of fiues 5 extending vertically of a chamber. In assembling the bricks to form the fiues 5, course 1 is laid asshown in Fig. 2, the hollow square portion of the brick forming one set of fiues indicated by reference numeral 5 and the project- ,ing portions 4 of adjacent checkers forming other formed by different portions of the checkerbricks,

they are of the same dimensions in both crosssection and length. It will be further noted that the brick structure shown results in the wall of flues 6 and 7 being of uniform thickness throughout and no walls of double thickness are obtained as a result of laying the bricks in the manner described.

In the modification shown in Figs. 3 and 5, the odd courses, 1. e., courses 1, 3, 5 and 7 of the checkerbrick are laid as previously described in connection with Fig. 2. However, the checkers of alternate courses, i. e., courses 2, 4, 6 and 8, are laid in staggered relation with respect to the checkers of odd courses. In Fig. 3, the bricks of the first course are outlined by broken lines, whereas the bricks of course 2 are shown in full lines. It will be seen that the sides 3 of the bricks in course 2 are laid to cover the joints between the bricks of the subjacent course; thus the checkerbricks of the even courses are supported upon the corners 8, 9, l0 and 11 (Fig. 2) of the bricks of the subjacent course. The checkers of the even courses are arranged in spaced relation and do not contact with each other as in the case of the checkers of the odd courses. A superimposed series of staggered courses laid in the manner shown in Fig. 3, affords a series of. straight paths'and tortuous paths for the gas passing through the checkerbrick, as shown in Fig. 5. The longitudinal, fiues formed in Fig. 2 will be interrupted by spaces 14 which allow the gas to change inflow from one flue to another, thereby effecting a short-circuiting, and consequent turbulence of the gas in its passages over the checkers, hence resulting in a longer period of exposure of gas to the hot brick.

In Fig. 6, I have shown a modified form of checkerbrick adapted to be laid-to form fiues as shown in Fig. 2 or in staggered relation, as shown in Fig. 3. This brick is in many respects similar to the form of checkerbrick shown in Fig. 4, with the exception that the underside of the sides 12 are formed with concave recesses 13. Thus, when the brick is laid in the manner shown in Fig. 2 to form longitudinal flues, the gases passing through one flue are not segregated from the gases in adjacent flues, but may intermingle and,

pass from one flue to another. It will be understood that therecesses may also be extended to the projections 15 so as to form openings in the fines formed by the abutting bricks.

In Fig. '7, I have shownstill a further modified form of the checkerbrick of my invention. A checkerbrick 42-is provided of substantially the same design as that of the brick of Fig. 4, differing only in the construction of one face thereof. Projections 45 of a size approximately one-fourth to one-third of the height of the checkerbrick are provided at the four points of intersection of the side walls 44 of the checkerbrick. As shown in Fig. 8, this specific form of checkerbrick is preferably laid in superposed courses such as courses 46 and 47, the individual bricks of which are staggered with respect to the adjacent upper and lower bricks, the side of the checkerbrick having the projections 45 thereon being laid downwardly so that the projections 45 rest on the center of the walls 44 of the underlying bricks. This construction provides a series of vertically staggered flues as shown in Fig. 9 which defines tortuous fiues for the passage of the blast and water gases.

The checkerbrick of this invention as hereinabove pointed out is particularly adapted for use in a water gas set such as shown in Fig. 1 wherein 16 designates a water gas generator containing a. fuel bed 1'1. A charging opening 18 for fuel is provided in the top of the generator. Steam may be supplied to the generator through pipe 21 and air for blasting the generator may be supplied through air blast pipe 22. The'g'en'erator 4 16 communicates through pipe 23 with the top of carburetor 25 which contains checkerwork 26 built up either in vertical fines or in staggered relation as has been previously described. Means may be provided for introducing an enriching medium such as oil into the top of the carburetor, said means preferably comprising an inlet at 2'7. A conduit 37 connects the bottom of the carburetor 25 with a superheater 29 which also contains checkerwork 30 of a type similar to that in the carburetor. The superheater is provided with a stack 32 for discharging waste gases during the blasting cycle. An off-take 31 leads from the top of the superheater through housing 39 which communicates with wash box 34. A secondary air opening 28 is provided in the connection 23 for the admission of air into the carbureto: and superheater during the blasting cycle. A conduit 35 leads from the base of the generator to housing 39. A suitable valve is positioned in housing 39 to control flow through the set as is well known.

The operation of the above described set usually comprises three cycles, i. e., a blasting cycle an up-run and a back-run In the blasting cycle, air is passed into the generator through line 22 and passes through the fuel therein, raising the temperature thereof until the fuel becomes an incandescent mass. The resultant blast gases are passed into the carburetor 25 through the conduit 23. Secondary air is admitted to the carburetor through pipe 28 and the mixtureof air and gas is ignited in its passage over the checkerbrick in the carburetor.

and the up-run cycle begun. Steam is passed into the base of the generator through inlet 21 and passes through the fuel bed to the conduit 23. The water gas formed as'a result of the reaction between the steam and the hot fuel, passes to the carburetor wherein it is carburetted by the addition of oil through oil inlet 27. The mixture of oil gas and water gas is fixed in its passage through the carburetor 25 and the superheater- 29. From the superheater, the water gas passes into the wash box 34 from which it passes through outlet 40 to a suitable holder. The uprun period'which preferably is of approximately two minutes duration is followed by a back- ,1

run period. Conduit 31 is closed to the flow of gas and steam is admitted at 33, the inlets 21 and 22 being closed. The steam admitted at 33 is superheated in its passage over the checkerwork in the superheater and carburetor and passed into the top of the generator downwardly through the fuel bed therein. The water gas formed passes out of the generator at 24 through the conduit 35 to the wash box 34.

It is apparent from the above described method of operation that if the successive phases are to be of the-order of three minutes, the checkerwork within the carburetor and superheater must be of a design to-quickly absorb and radiate heat. The brick of the present invention in providing a thin wall together with the requisite structural strength and being of such a shape as can be laid to form fiues, the walls of said flues being of a uniform thickness throughout the structure, is peculiarly adaptable for carburetted water gas operation involving relatively short run periods. By reason of ,the single wall thickness throughout, the rate of absorption and radiation of heat throughout the chambers will be uniform, which obviously would not be the case if there were portions of the wall such as the joints between adjacent bricks which were not of uniform thickness. Such uniform rate of heat transfer increases the efficiency and ease of control of the chambers.

Furthermore, the relatively simple design of the brick coupled with its structural strength affords a quick and easy method of laying in either an arrangement to produce vertical flues or in staggered relationship to provide tortuous passages. The checkerbrick described herein, by reason of its large area of effective exposed surface per cubic foot of ceramic material affords a I maximum of heat exchange surface with the minimum volume of brick, thus increasing the heat transfer efficiency of the system.

The invention, as hereinabove set forth, is

embodied in a particular form of constructi n, 1

ing beyond the corner edges of the parallelepiped V a distance equal to one-half the length of said wall, said checkerbrick being adapted to be arranged with other like checkerbrick to form flues so that the hollow portion of each brick defines one flue, and the projecting portions at a corner thereof cooperate with projecting portions at a corner of a contiguous brick to define a like flue, and one face of said brick transverse to said flues having projections thereon at the intersections of said walls, said projections being arranged to space superimposed bricks apart so as to provide a passage between adjoining flues.

2. A checkerbrick comprising a hollow parallelepiped, the adjacent side walls of said parallelepiped being substantially perpendicular to each other, each of said walls being provided at its ends with projecting portions, each extending beyond the corner edges of the parallelepiped a distance equal to one-half the length of said wall, said checkerbrick being adapted to be arranged with other like checkerbrick to form flues so that the hollow portion of each brick defines one flue, and the propecting portions at a corner thereof cooperate with projecting portions at a corner of a contiguous brick to define a like flue, and one face of said brick-transverse to said flues having projections thereon, said projections being arranged to space superimposed bricks apart so as to provide a passage between adjoining flues- 3. A checkerbrick comprising a hollow parallelepiped, the adjacent side walls of said parallelepiped being substantially perpendicular to each other, each of said walls being provided at its ends with projecting portions extending beyond the corner edges of theparallelepiped, said checkerbrick being adapted to be arranged with other like checkerbrick so that the hollow portions of each brick define one flue and the projecting portions at each corner cooperate with the projecting portions of other like brick at corners of contiguous bricks to define other like flues, the walls of said flues being of uniform thickness throughout and one face of said bricks transverse to said flues having propections thereon, said projections being arranged to space superimposed bricks apart so as to provide a passage between adjoining flues.

CHARLES H. HUGHES. 

